The present disclosure relates generally to a battery gasket for sealing an opening of a battery case, and an alkaline battery using the same.
A cylindrical alkaline battery is configured by placing battery components in a battery case, and sealing an opening of the battery case with a gasket.
In general, a gasket includes a cylindrical boss portion having a through hole in which a current collector is inserted, a rim portion for sealing an opening of a battery case, and a connecting portion for connecting the boss portion and the rim portion. The gasket thus configured is integrally injection molded by injecting a molten resin into an injection mold.
In injection molding the gasket, a gate through which the molten resin is injected in the injection mold may be arranged at various positions of the injection mold. For example, when the gasket includes a thin portion formed in the connecting portion to function as a safety vent for preventing the explosion of the battery, the gate is preferably arranged in the injection mold to correspond to an end face of the boss portion of the gasket so that the molten resin can smoothly flow into the injection mold (see, e.g., Published Unexamined Japanese Patent Applications Nos. 2005-093204, 2004-134168, and H08-167405).